Quantum hypothesis testing for exoplanet detection

TL;DR

This paper introduces quantum hypothesis testing techniques to improve exoplanet detection via direct imaging, significantly reducing error probabilities when distinguishing faint secondary sources near bright stars.

Contribution

It demonstrates the application of quantum state discrimination to enhance exoplanet detection, providing optimal measurement strategies for weak sources with small angular separations.

Findings

Error probability can be reduced by a factor of 1/ε for weak sources.

Quantum methods outperform classical imaging in low-intensity regimes.

Identifies optimal linear-optical measurements for exoplanet detection.

Abstract

Detecting the faint emission of a secondary source in the proximity of the much brighter source has been the most severe obstacle for using direct imaging in searching for exoplanets. Using quantum state discrimination and quantum imaging techniques, we show that one can significantly reduce the probability of error for detecting the presence of a weak secondary source, even when the two sources have small angular separations. If the weak source has relative intensity $\epsilon \ll 1 $ to the bright source, we find that the error exponent can be improved by a factor of $1/\epsilon$. We also find the linear-optical measurements that are optimal in this regime. Our result serves as a complementary method in the toolbox of optical imaging, from astronomy to microscopy.